The same reason the Go 1.9 changelog won't be discussed in political forums, opinions on USA's political landscape surely has a better home on the Internet than here.
Most sites are either echo chambers or fighting cages. The civility of Hacker News makes it a great place for not having shouting matches. Perhaps you know of other political sites with a HN-like community?
Golang 1.9 changelog wont be discussed in many places because it's a niche topic. Politics affects everyone, and therefore should be discussed everywhere.
Again these same types of arguments I've seen happen back home. People used to say stuff like "oh my god do we have to discuss politics here too??!" End result: the country slid down to authoritarianism and now everyone is fucked, even those who insisted on staying in their own little niche bubbles.